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promise on array and streams. http://stackoverflow.com/q/22475917/157260
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var fs = require('fs'), | |
path = require('path'), | |
Promise = require('rsvp').Promise, | |
request = require('request'), | |
files = [ | |
'https://www.google.com/images/srpr/logo11w.png', | |
'http://rack.1.mshcdn.com/media/ZgkyMDEzLzA5LzE2L2JjL0Jpbmdsb2dvb3JhLmFkYjJkLnBuZwpwCXRodW1iCTEyMDB4OTYwMD4/996d9598/35b/Bing-logo-orange-RGB.png', | |
'http://assets.fontsinuse.com/static/use-media-items/15/14246/full-2048x768/52c4c6bc/Yahoo_Logo.png' | |
]; | |
var process = files.map(function (url) { | |
return downloadFile(url).then(extractFile); | |
}); | |
Promise.all(process) | |
.then(function () { | |
console.log('done processing'); | |
}) | |
.then(null, function () { | |
console.log('error processing'); | |
}); |
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var fs = require('fs'), | |
path = require('path'), | |
Promise = require('rsvp').Promise, | |
request = require('request'), | |
files = [ | |
'https://www.google.com/images/srpr/logo11w.png', | |
'http://rack.1.mshcdn.com/media/ZgkyMDEzLzA5LzE2L2JjL0Jpbmdsb2dvb3JhLmFkYjJkLnBuZwpwCXRodW1iCTEyMDB4OTYwMD4/996d9598/35b/Bing-logo-orange-RGB.png', | |
'http://assets.fontsinuse.com/static/use-media-items/15/14246/full-2048x768/52c4c6bc/Yahoo_Logo.png' | |
]; | |
// waterfall - process next file only after previous one is done | |
files.reduce(function (sequence, next) { | |
return sequence.then(function () { | |
return downloadFile(next).then(extractFile); | |
}); | |
}, Promise.resolve()) | |
.then(function () { | |
console.log('done processing files'); | |
}) | |
.then(null, function (err) { | |
console.log('error processing files', err); | |
}); | |
function downloadFile(url) { | |
return new Promise(function (resolve, reject) { | |
var destination = path.basename(url); | |
request(url).pipe(fs.createWriteStream(destination)) | |
.on('close', function () { | |
resolve(url); | |
}) | |
.on('error', function (err) { | |
reject(err); | |
}); | |
}); | |
} | |
function extractFile (url) { | |
var file = path.basename(url); | |
if (path.extname(file) !== '.zip') { | |
return Promise.resolve(url); // NOOP | |
} | |
// extract file | |
return Promise.reject(new Error('not implemented')); | |
} |
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var fs = require('fs'), | |
path = require('path'), | |
request = require('request'), | |
Rx = require('rx'), | |
files = [ | |
'https://www.google.com/images/srpr/logo11w.png', | |
'http://rack.1.mshcdn.com/media/ZgkyMDEzLzA5LzE2L2JjL0Jpbmdsb2dvb3JhLmFkYjJkLnBuZwpwCXRodW1iCTEyMDB4OTYwMD4/996d9598/35b/Bing-logo-orange-RGB.png', | |
'http://assets.fontsinuse.com/static/use-media-items/15/14246/full-2048x768/52c4c6bc/Yahoo_Logo.png' | |
]; | |
Rx.Observable.fromArray(files) | |
.selectMany(function downloadFile(url) { | |
var subject = new Rx.AsyncSubject(), | |
destination = path.basename(url); | |
request(url).pipe(fs.createWriteStream(destination)) | |
.on('close', function () { | |
subject.onNext(url); | |
subject.onCompleted(); | |
}) | |
.on('error', function (err) { | |
subject.onError(err); | |
}); | |
return subject; | |
}) | |
.filter(function (file) { | |
return path.extname(file) === '.zip'; | |
}) | |
.selectMany(function unzip (file) { | |
return Rx.Observable.throw(new Error('not implemented')); | |
}) | |
.subscribe(function onNext () { | |
}, function onError (err) { | |
console.log(err); | |
}, function onCompleted () { | |
console.log('done'); | |
}); |
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